Function TestCounterExemplar

prometheus/counter_test.go:261–318

(t *testing.T)

}

func TestCounterExemplar(t *testing.T) {
	now := time.Now()

	counter := NewCounter(CounterOpts{
		Name: "test",
		Help: "test help",
		now:  func() time.Time { return now },
	}).(*counter)

	ts := timestamppb.New(now)
	if err := ts.CheckValid(); err != nil {
		t.Fatal(err)
	}
	expectedExemplar := &dto.Exemplar{
		Label: []*dto.LabelPair{
			{Name: proto.String("foo"), Value: proto.String("bar")},
		},
		Value:     proto.Float64(42),
		Timestamp: ts,
	}

	counter.AddWithExemplar(42, Labels{"foo": "bar"})
	if expected, got := expectedExemplar.String(), counter.exemplar.Load().(*dto.Exemplar).String(); expected != got {
		t.Errorf("expected exemplar %s, got %s.", expected, got)
	}

	addExemplarWithInvalidLabel := func() (err error) {
		defer func() {
			if e := recover(); e != nil {
				err = e.(error)
			}
		}()
		// Should panic because of invalid label name.
		counter.AddWithExemplar(42, Labels{"in\x80valid": "smile"})
		return nil
	}
	if addExemplarWithInvalidLabel() == nil {
		t.Error("adding exemplar with invalid label succeeded")
	}

	addExemplarWithOversizedLabels := func() (err error) {
		defer func() {
			if e := recover(); e != nil {
				err = e.(error)
			}
		}()
		// Should panic because of 129 runes.
		counter.AddWithExemplar(42, Labels{
			"abcdefghijklmnopqrstuvwxyz": "26+16 characters",
			"x1234567":                   "8+15 characters",
			"z":                          strings.Repeat("x", 63),
		})
		return nil
	}
	if addExemplarWithOversizedLabels() == nil {
		t.Error("adding exemplar with oversized labels succeeded")
	}
}